Embodiments relate to settable compositions and, more particularly, embodiments relates to the use of alkali aluminates and alkali silicates with cement kiln dust to form a settable composition for use in subterranean operations.
A natural resource such as oil or gas residing in a subterranean formation can be recovered by drilling a wellbore into the formation. A wellbore is typically drilled while circulating a drilling fluid through the wellbore. Among other things, the circulating drilling fluid may lubricate the drill bit, carry drill cuttings to the surface, and balance the formation pressure exerted on the wellbore. One problem associated with drilling may be the undesirable loss of drilling fluid to the formation. Such lost fluids typically may go into, for example, pre-existing fractures, induced fractures, cracks, vugs, channels, or other openings through which fluid may be lost. This problem may be referred to as “lost circulation,” and the sections of the formation into which the drilling fluid (or other fluid) may be lost may be referred to as “lost circulation zones.” The loss of drilling fluid into the formation is undesirable, inter alia, because of the expense associated with the drilling fluid lost into the formation, loss of time, additional casing strings and, in extreme conditions, well abandonment. In addition to drilling fluids, problems with lost circulation may also be encountered with other fluids, for example, spacer fluids, completion fluids (e.g., completion brines), fracturing fluids, and cement compositions that may be introduced into a wellbore.
A number of techniques have been developed for combating lost circulation one of which involves the placement of lost circulation materials into the lost circulation zone. Conventional lost circulation materials may include fibrous, lamellated or granular materials. The lost circulation materials may be placed into the formation, inter alia, as part of a drilling fluid or as a separate lost circulation pill in an attempt to control and/or prevent lost circulation. Another technique that has been developed to control lost circulation involves the placement of a settable composition into the wellbore to seal the lost circulation zone. For a number of reasons, however, these techniques may not provide a desirable level of lost circulation control in all circumstances.